extracting strings using regular expression

Question

I have the following strings:

1. LOW QUALITY PROTEIN: cysteine proteinase 5-like [Solanum pennellii]
2. PREDICTED: LOW QUALITY PROTEIN: uncharacterized protein LOC107059219 [Solanum pennellii]
3. XP_019244624.1 PREDICTED: peroxidase 40-like [Nicotiana attenuata]
4. RVW92024.1 Retrovirus-related Pol polyprotein from transposon TNT 1-94 [Vitis vinifera]
5. hypothetical protein VITISV_035070 [Vitis vinifera]

How to extract the below strings from the above strings?

1. cysteine proteinase 5-like
2. uncharacterized protein LOC107059219
3. peroxidase 40-like
4. Retrovirus-related Pol polyprotein from transposon TNT 1-94
5. hypothetical protein VITISV_035070

Answer 1

s = '''LOW QUALITY PROTEIN: cysteine proteinase 5-like  [Solanum pennellii]
PREDICTED: LOW QUALITY PROTEIN: uncharacterized protein LOC107059219 [Solanum pennellii]
XP_019244624.1 PREDICTED: peroxidase 40-like [Nicotiana attenuata]
RVW92024.1 Retrovirus-related Pol polyprotein from transposon TNT 1-94 [Vitis vinifera]
hypothetical protein VITISV_035070 [Vitis vinifera]'''

import re
rgx = '(:?)\s([\w\s-]+)\s(\[.+\])'

list1 = []
for m in re.findall(rgx, s):
    list1.append(m[1])

print(list1)

Output

['cysteine proteinase 5-like ',
 'uncharacterized protein LOC107059219',
 'peroxidase 40-like',
 'Retrovirus-related Pol polyprotein from transposon TNT 1-94',
 'hypothetical protein VITISV_035070']

Look up https://regex101.com/r/HATKMa/1 for the explanation in detail.

Answer 2

I think this problem don't need regex. I would prefer following solution because it is easy to understand

st = "PREDICTED: LOW QUALITY PROTEIN: uncharacterized protein LOC107059219 [Solanum pennellii]"
st.split(":")[-1].split("[")[0].strip()